High-order multiphoton fluorescence of organic molecules in solution by intense femtosecond laser pulses.
The five and possibly seven-photon fluorescence was observed for organic molecules in solution for the first time. A high-intensity laser enabled us to measure the properties of the high and any-order processes, and the emission could be directly visualized by the eye. These results showed that the common two-photon microscope could be upgraded to the higher order multiphoton microscope by choosing suitable excitation wavelengths. The multiphoton absorption cross sections differed by a factor of 10(33) as the order of the multiphoton process increased.
Yatsuhashi
Tomoyuki
T
Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 Japan. tomo@sci.osaka-cu.ac.jp
Ichikawa
Soh
S
Shigematsu
Yukari
Y
Nakashima
Nobuaki
N